FIELD OF THE INVENTION
The invention relates to a device for in-register positioning of a printing plate for mounting on a plate cylinder of a printing press, with at least two positioning pins engageable exactly into recesses on a printing plate leading edge for in-register positioning, and including sensors for detecting the exact engagement and transmitting a corresponding signal.
Devices of this general type have become known heretofore from the published European Patent Documents EP 0 581 212 A1 and EP 0 551 976 B1. In these devices, the leading edge clamping device of a plate cylinder has positioning pins attached thereto which, in the exact engagement position thereof, close a circuit via the inserted printing plate and emit a signal. With these devices, however, it is not possible to prevent the correct positioning of a printing plate from being signalled, even when it is inserted in a laterally transposed manner, and the laterally transposed insertion therefore remains unrecognized. Furthermore, checking the correct positioning of a printing plate is restricted to insertion into the leading edge clamping device of a plate cylinder. Moreover, only printing plates made of electrically conductive material can be detected.